Apparatus for pneumatically delivering material.



G. H. GILBERT.

APPARATUS FOR PNEUMATICALLY DELIVERING MATERIAL;

' APPLICATION FILED DEC. 13. IEIIZ. Lmmm Patented July 13, 1915.

I a SHTSSHEET I.

WITNESSES: I [Ni EA G. H. GILBERT.

APPARATUS FOR PNEUMATICALLY DLIVERING MATERIAL.

APPLICATION man DEC. I3. 1912.

1 1%,775. Patented July 13, 1915.

3' SHEETS-SHEET2.

. A 43 Fig. 4 39 /9 25 30 W/TNESSES: I33 INVENTOI? e. H. GILBERT. APPARATUS E03 PNEUMATICALLY DELIVERING MATERIAL. APPLICATION FILED DEC. I3, IQIZ INVENTOR ATTORNEY s'rns .ar

ion;

GILBERT H. GILBERT, OF NEW YORK, N. Y.

mamas.

. Pneuniatically Delivering Material, of which the following'is a specification. v

This invention involves a new vand 1m proved apparatus for automatically acting upon a powdered, granular or other finely subdivided material, by gas pressure and more particularly for placing it under gas pressure and delivering it along a conduit by said pressure.

It is adapted for use in various different arts, for instance it may be employed. for pneumatically conveying or elevating flour, grain, sand, or other material from one place to another, or it may be employed in connection with sand blasting or other similar apparatus used in embrasive work or it may be used for decorating purposes where it is desired to deliver a finely subdivided material against a prepared surface.

In'order that the scope of my invention may be fully understood and the range of equivalents may be clear I will explain in detail one embodiment of my invention especially designed for use in cement construction. I

In one type of'apparatus now in use cement, or sand and cement is blown from a nozzle and united while in transit with Water which combines with the cement and 'forms a self-hardening mixture upon the surface against which the nozzle is directed. The preferred embodiment of. my invention has been designed for the agitation and mixing of thecement or the cement and sand or gravel or both, and. the automatic delivering of separate charges from a receiving chamber through an air lock to a pressure chamber in which the agitation continues and from which the material is delivered by the air or other gas pressure to the nozzle. This agitation may be secured by advancing the material along a helical or spiral passageway within a drum or other rotating body so that the rotation serves not only to effect the agitation but also to effect the continuous advancement of the material.

An important feature of my invention resides in the means for controlling the ad- Specification of Letters Patent.-

Patented July 13, 1915.

Application filed December 13, 1912. Serial No. 736,484..

mission of the material to the air lock or intermediate chamber and for controlling the delivery of the material from said air lock to the high pressure chamber.

A further important feature resides in the means -whichl have designed for automatically controlling the air pressure in thisintermediate chamber or air look so that the pressure in said air lock may be equalized with that of the adjacent chamber from which it receives the material or that of the chamber to which it delivers the material, at the proper time. This permits the valve or other mechanism past which the material is delivered to automatically open and close by gravity at the proper time during the rotation of the chambers about a common axis. a

The chambers may be rotated or otherwise moved by the use of power from any suitable source and the high pressure chamber may receive air or other gas from any suitable source, but I may employ as an important feature of my invention automatic governing means whereby the interruption of the normal operation of the apparatus by clogging in the delivery pipe -or the production in any other way of an excessive pressure in the high pressure chamber will act to antomatically govern the prime mover by stopping or retarding it. Preferably I secure this result by using a prime mover operated by a gaseous fluid and deliver the exhaustdirectly to the high pressure chamber of the apparatus. The prime mover may be an internal combustion engine, a compressed air motor of the turbine type, or other suitable device which may be stopped or retarded by the closing or restricting of the exhaust conduit. 13y delivering the exhaust directly into the high pressure chamber, the creation .of an excessively high pressure therein will prevent the free delivery of the exhaust from the prime mover and retard or stop the latter. On the other hand any abnormal reduction of gas pressure in the high pressure chamber will permit a more free escape of the exhaust from the, prime mover and permit the latter to increase its speed.

' The receiving chamber, the air lock and the delivering chamber may be arranged in any suitable manner in respect to each other, but preferably the receiving chamber is so designed that the material will be received througha screen of proper mesh and thus the delivery of large solid masses of material which might clog or interrupt the normal operation or the machine is prevented.

Having thus set forth in a general way the nature and 'objects of my invention, 1 call attention to the accompanying. drawings forming a part of this specification and in which similar reference characters indicate corresponding parts in the several views.

Figure l is a top plan view oi a portable plant embodying my invention and adapted for use in the mixing of cement or cement and sand orgravel or both and the delivering of the latter pneumatically to the point at which itis to be used. Fig. 2 is a side elevation of the mechanism illustrated in Fig. 1; Fig. 3 is a transverse section through the drum substantially on the line 3-3 of Fig. 4:; Fig. 4 is a central longitudinal sec tion of the drum, said section being taken substantially on the line 4-4 of Fig. 3, and Figs. 5, 6, 7 and 8 are end views of the drum showing the latter in four difierent positions which it occupies during this rotation about a substantially horizontal axis.

As previously stated my invention may be embodied in a large number of difierent forms of apparatusand may be utilized for the treating or delivering of various dilten out materials for different purposes. The form illustrated in the drawings and hereinafter described in detail is only oneembodiment which the invention may assume even for the purpose of mixing and pneumatically delivering cement, cement and sand, or-cement sand and gravel. I have illustrated this particular embodiment as in a portable form thus facilitating the quick transportation from one place to another. I have illustrated the machine as mounted upon a truck having a frame, platform or base 10 and suitable supporting wheels. The main portion of the apparatus is embodied in a substantially cylindrical drum 11 supported with its axis substantially horizontal or slightly inclined and upon suitable antifriction rollers llat one end and a trunnion at the other. Any suitable means may be employed for rotating the drum but preferably it is provided with a gear wheel 13 in the form of a peripheral series of gear teeth.

The drum has a central opening 14 at one end through which the material may be delivered and intermediate of the ends is a transverse wall or partition 15 open for a" short distance along one side to permit the material topass the same. Betweenthis partition or wall and the open end there is preterably mounted an annular screen 16 concentric t0 the peripheral wall and encircling acchamber into which the material may be delivered in any suitable manner through the open. end 14. In the annular chamber between this screen and the peripheral wall I mount suitable means for advancing the material len thwise of the drum as the latter rotates. This means may be in the form of helical or convolute webs, partitionsor flanges, but in the preferred embodinient I employ two helical flanges or plates 17 and 18 secured to the peripheral wall. The first of these conveying members,

that is the flange 1? which is nearest the tively advance the material. This flange terminates at the transverse partition 15 and the latter has an opening therethrough opposite the final portion of this flange.

Within the space between the end wall 19 and the partition 15 is a spiral partition 20 having its innermost portion adjacent to the center of the drum and having its outer portion adjoining the periphery of the drum as is clearly illustrated in Fig. 3. Two pivoted valves 21 and Q2 operate, when in engagement with their respective valve seats :23 and '24, to subdivide the said spiral passageway into a central chamber 25 hereinafter referred to as the high pressure chamher, a second chamber 26 hereinafter re ferred to 'as the intermediate chamber or air lock, and an outer chamber 27 which serves as a portion of the receiving chamber. The end walls of the chambers 25 and 26 are formed by the partition 15 and the end wall '19 while the receiving chamber 27 has the wall 19 at one end and is open at the other into the annular space between the screen 16 and the peripheral wall of the drum. It will be noted from a consideration of Figs. 3 and i that, upon rotating the drum in the direction indicated by the arrow in Fig. 3. material which has been delivered through the open end 14 andqvhich has passed through the screen 16, will headvanced into the chamber :27 and then, except for the Valves 21 and 22,,. will be moved inward toward the center, ofthe drum by the spiral partition 20. I

For maintaining the desired air pressure in the high pressure chamber 25 and for permitting the delivery ot the material under .air pressure from this chamber any suitable means may be employed which will not interfere with the rotation of the drum. "in the drawings .l have illustrated the drum head 19 provided with an outwardly proecting sleeve '28 constituting a trunnion and through which extends two concentric spaced pipes 29 and 30. The outer pipe 29 terminates in a casing 31 atits outer end and through which the pipe 30 may extend. An air tight connection between the outer pipe and the sleeve 28 is efl'ected by a suitable packing gland 32 so that both pipes may remain stationary during the rotation of the drum. A suitable air supply conduit 33 may be connected to the casing so as to deliver air through the annular space between the pipes 29 and 30 into the high pressure chamber 25 and from this chamber the air may escape together with the material through the pipe 30. As these pipes are centrally located in respect to the drum and the sleeve 28 constitutes a hearing or trunnion for the drum, it is evi dent that the rotation of the drum does not disturb the connections to the source of gas supply or the nozzle. The inner end of the partition may be formed in any other way to facilitate the delivery of the material to the central pipe along with the gas under.

pressure.

One of the lmportant features of my invention involves the automatic controlling of the passage for material and air leading to and from the airlock or intermediate chamber 26. As illustrated in Fig. 3 the twovalves 21 and 22 which control the passage of the material are mounted at substantially diametrically opposite points and each is so mounted that it may swing to open position and leave a substantially uninterrupted pathway for the material as the drum rotates. The specific character of the valve and valve seat is immaterial as various different forms may be employed to secure substantially the same result. The valves are illustrated as being pivoted to the outer or peripheral side of the passageway so that when open they may swing toward or into engagement with the outer wall of the drum. Furthermore, they are so mounted that in swinging to open position they move in the direction in which the material travels along the passageway.

For controlling the air pressure Within the air lock I provide a by-pass 34 having one end 35 in open communication with the high pressure chamber 25 and the opposite end 36 in open communication With the air lock. Nithin this by-pass is a valve 37 of any suitable character and provided with a valve lever haying oppositely disposed outwardly extending arms 38 and .39. The arm 38 is providedwith a weight 40 of sufiicient mass to insure' the proper automatic move ment oi the valve as the drum rotates. The head of the drum is provided with a stop 11 to limit the swinging movement of the weighted arm 38 in one direction. As the valve 37 controls the air passage 34. between the high ressure chamber andthe air lock,

K the opposite ends of the by-pass or pipe 34 are upon opposite sides of the valve 21. The valve 37 is adjacent to the main valve 21 and the pivot pin 42 of the latter pro-' jects outwardly at the end of the drum and into the path of the arm 39 of the lever. A portion of the pin 42 is cut away so that its position determines whether or not the arm 39 may pass. The head of the drum'also carries a by-pass 43 through which the air may escape from the air lock to the atmosphere. This by-pass may deliver into the receiving chamber 27 if desired but this is not essential and it is somewhat simpler to connect one end 44 of the by-pass to the air lock and to permit theopposite end 45 to discharge directly to the atmosphere. Within this by-pass there is a valve 46 similar to the valve 37 and this valve has a valve lever with arms 47 and 48. The arm 47 carries a weight 49 which may engage with a stop 50 on the head of the drum and the valve 22 has its pivot pin 51 projecting'out through the end of the drum and into the path of the valve lever arm 48, a portion of said pin 51 being cut away the same as the pin 42.

The automatic operation of the valves 21, 22 37 and 46 may be briefly set forth as follows: The central chamber 25 is constantly maintained under the desired pressure of air or other gas through the pipe 33 and material is continuously delivered to the receiving chamber 27 by the helical conveyers 17 and 18. With the parts in the position indicated in Fig. 5,'it will be noted that the valves 22 and 16 are open and the valves 21 and 37 closed, the air pressure in the air lock 26 being the same as in the receiving chamber 27 so that the charge of material may freely pass the valve 22. In fact mostof the charge of material will have passed into the chamber 26 before the parts reach the position indicated in Fig. 5. As the drum rotates in the direction indicated by the arrow, one-quarter turn from the position shown in Fig. 5 to that shown in Fig. 6, the valve 22 will have swung to closed position. It will be noted that during this one-quarter turn the valve arm 48 engages with the stud 51 so as to prevent the weight 49 from swinging toward the stop 50 until the valve 22 has reached such a position that the projecting part oi the valve pivot pin 51 will have turned out of the path of the valve arm 48. The instant that this occurs which may be justprior to the seating of the valve 22 the lever 48 will suddenly swing through approximately onequarter revolution until the weight seats on the stop 50 as is shown in Fig. 6 and the valve 46 will thus suddenly close. Al; the same time the valve 21 will have reached the bottom position and the weight of the nm-. terial in the intermediate chamber pressing against said valve and also the action of gravity on the valve itself, will tend to the position shown. in Fig 6.

swing the valveto open position. The only influence resisting this is the difl'erence in air pressure between the high pressure chamber and the air look. It will be noted that the weight 40 of the valve 37 rests upon the stop 41 when the parts are in the po sition. shown in Fig. 5 and therefore, there will be no rotation of the air valve during the first part of the rotative movement of the drum from the position shown in Fig. 5. When the drum is rotated to such a position that the lever 38 is vertical or suthciently near to vertical. to permit the weight 40 to swing over away from the stop 4.1, the airvalve 3? will suddenly open and the air pressure in the air lock and the high pressure eha'inberwill be equalized and there will no longer be any tendency resisting the opening of the va ve 21 and the latter will swing outwardly and downwardly to This occurs after the valves 22 and 46 have closed. This movement of the 8.1!" valve 37 carries the lever 39 past the pivot 42 so that its return movement \villrbe prevented until the valve 21 has again closed. From the position shown in Fig. (7- the drum continues to rotats another one-quarter turn unti the parts are in the position shown in Fig. but dun ing this one-quarter turn there is no change in the relative positions of the valves. The

inlet 22 to the air lock is closed, the air outlet valve 46 is closed, the outlet valve 21 for the material from the air lock to the high pressure chamber is open, as is also the air valve 37. Inthe meantime the material which was in the airlock has been advanced into the high pressure chamber 25. As the drum continues' to rotate from the position shown in- Fig. 7 toward the position shown in Fig. 8, the material in the receiving chamher will accumulate against the valve 22 and the action of gravity will slowly swing the valve 21 toward its closed position. When it reaches this position the'liever 39 which has been pressed against the pivot pin 42 will be released and the vhlve 37 will suddenly move to closed position under the influence of gravity on the weight 4-0. Just prior to this the weight 49 will have to led over away from the stop 51 and closed the air communication between the high pressure chamber and the air lock. The closing of this communication and the opening. ofthe valve 46 relieves the air look from hi gh pressure and reducesthe pressure on the inner side of the valve 22 so that the material'pressing against it aided by gravity, will swing the valve 22 open and permit the material to pass into the air lock as the drum rotates. The successive steps of this operation may be briefly summarized as follows: The two main valves 21 and 22 are opened by gravity and the accumulated material pressing against them; but before either of these valves operates the corresponding air valve operates so as to neutralize the air pressure upon opposite sides of said main valves. The valves 21 and 22 thus swing slowly to closed positiomand rather suddenly to open position. The air valves have a rapid movement in each direction, the movement in one direction being controlled by the overbalancing of the corresponding weights and the return movement being prevented until the corresponding main valves have reach.edclosed position. The pressure in the air lock is thus substantially equal to that of the atmos phere through one-half revolution andie ual to that of the high pressure chamber ur ing the remaining half revolution and the,

air lock takes in a full charge automatically, during each revolution of the drum and delivers it to the high pressure chain- I have illus'trateti one particular form of valve mechanism which will operate to secure this result but it is evident that'various changes may be made from that shown without in any way departing from the spirit of my invention. Furthermore, I have illustrated only a single air lock for delivering the material from atmospheric pressure to the high pressure chamber, but it is of course evident that I am not to be limited to this specific length of spiral passfigeway or to the number of air locks shown, or to the loeating of the chambers in the-same transverse plane. The construction and arrangements of the parts will of course vary with the character of the material dealtwith and the specific purpose for which the apparatus isto be employed.

Although in some embodiments of my invention the drunr may be rotated by any suitable source of power and theair or other gas be delivered to the drum from any suitable source, yet a saving may be effected and an automatic governing action secured by utilizing a prime mover operated bya gaseous fluid, such for instance as a compressed air motor, an internal combustion jengine, or the like. In the specific form illustrated I employ a compressed air turbine 52 operated from a source of air supply-n t shown. The power from the main shaft 53 is transmitted to an intermediate shaft 54 through a train of gears inclosed in a gear case 55 and the drum is rotated by a pinion 56 on thesaid intermediate shaft and meshing with the gear teeth 13 on the; drum. The train of gears is preferably sujhh as to materially reduce the speed fromithat'to which a compressed. air turbine or inarily operates. The turbine is designed to, deliver this exhaust at a pressure materially; above that of the atmosphere and this erfhaust may be conduct ed through a conduit 55 to the inlet pipe33 mamas of the drum. By-this arrangement .I secure the desired governing action of the entire apparatus and, economize power, as it is evidentthatin case the drum or delivery conduit from the latter should become clogged or otherwise obstructed the pressure in thehigh pressure chamber-of the drum will'continue to increase until it creates a back pressure-on the air turbine approaching the pres sure of the source of 'air supply to the turbine and thus automatically reduces the speed of said turbine or stops the latter.

This prevents the continued rotation of the drum which might serve to further clog the drum or interfere with the proper action of the valves 21 and 22. Instead of the air turbine shown it is evident that an internal combustion cnginemight'be employed which would avoid the necessity of an outside source of gaspressure and the exhaust'lrom the engine to be delivered directly into the drum. Of course this would only be feasible where the presence of products of combus tion or the presence of an increased temperature in the high pressure chamber and thedelivery conduit therefrom would not interfere with the proper operation of the apparatus. Where cement, sand and gravel are.

to 'be blown through the delivery conduit by gas pressure it is evident that the exhaust from the gas engine mightbe employed without detrimental action.

Having thus described my invention, Ihat I claim as new and desire to secure by Letters Patent is:-

l. An apparatus of the class described comprising a series of compartments the first of which is at atmospheric pressure, means for maintaining a pressure in the last of said chambers materially above atmospheric pressure and means for advancing the material from said chamber at atmospheric pressure to said high pressure chamber by the bodily movement of said chambers.

2. An apparatus of the class described comprising a series or compartments the first of which is at atmospheric pressure, means for maintaining a pressure in the last of said chambers materially above atmospheric pressure, means for advancing the material from said chamber at atmospheric pressure to said high pressure chamber by the bodily movement of said chambers, and means for delivering the material from said high pressure chamber by the gas pressure.

chamber, and means for automatically advancing material through said chambers in succession by the bodily movement of said chambers.

e. In combination, a low pressure chamber, an'air look, a high pressure chamber and means for automatically opening and closing communication between said chamgers by the bodily movement of said chamers.

5. In combination, a low pressure cham her, a high pressure chamber and an intermediate air lock maintained alternately at the pressures of the high pressure and low pressure chambers respectively, and means for delivering material from said low pressure chamber to said air lock and from said air lock to said high pressure chamber by the bodily movement of said chambers.

6. A bodily movable container having a low pressure chamber,- a high pressure chamber, an intermediate air lock maintained alternately at the pressures of said high pressure and low pressure chambers, valves controlling communication between said chambers and means for automatically controlling said valves.

7. ,A. bodily movable container having a low pressure chamber, an air lock, a high pressure chamber, valves controlling the delivery of material through said chambers in succession, and a valve controlled by-pass independent. of said valve for controlling the gas pressure in said air lock.

8. In combination, a low pressure chamme her, an air look, a high pressure chamber, valves, controlling the delivery of material through said chambers in succession, and a valve controlled by-pass independent of said valve for controlling the gas pressure in said air lock, said valves operating automatically to permit the passage of material upon the bodily movement of said c ambers.

9. In combination, a low pressure chamher, an air lock, a high pressure chamber, valves controlling the delivery of material through said chambers in succession, and a valve controlled by-pass independent of said valve for controlling the gas pressure in said air lock, said valves operating auto- 5 matically to permit the passage of material upon the rotation of said chambers about a common axis.

10, A rotatable drum having partitions therein subdividing it into a receiving chamher, an air lock, and a high pressure cham her, and means for automatically opening communication between said air lock and said chambers alternately.

11. A drum having partitions therein s'ubdividing it into a receiving chamber, an air lock, and a high pressure chamber, and means for rotating said drum.

12. A drum having partitions therein subdividing it into a receiving chamber, an air Jill are

t ll

Elli

lock, and a high pressure chamber valves controlling communication between said air lock and said chambers, and means for con-.

trolling said valves by the rotation of said drum.

13. A rotatable container having a spirally disposed passageway and valves subdividing said passageway into separate chambers or compartments. 7

14:. An apparatus of: the class described having a spirally disposed passageway, valves subdividing said passageway into separate chambers or con'ipartments, means for maintaining one oi said compartments at a pressure above that of the atmosphere and means for rotating said apparatusto advance material along said passage-way.

15. An apparatus of the class described having a spirally valves subdividingsaid passageway into separate chambers or compartments, and means for rotating said apparatus to advance material along said passageway.

16. An apparatus oi the class described having a curved passageway, vidiug said passageway into separate compartments, said valves operating automatically to permitthe movement of material. along said passageway upon the rotation of said apparatus.

1'7. An apparatus of the class described having a curved passageway, valves subdividing said passageway into separate compartments, and operating automatically upon the rotation of said apparatus, and means for maintaining one of said compart" ments under a gas pressure higher than that of the atmosphere.

18. An apparatus of the class described having a curved passageway along which material may advance by the rotation of said apparatus and valves subdividin said passageway into separate compartments and operating automatically to permit said move merit of the material during said rotation.

19. An apparatus of the class described having a passageway along which material may advance by the rotation oi: said apparatus and means for delivering said material from said passageway by gas pressure.

20. An apparatus of the class described having a curved passageway along which materia may advance by the rotation of said apparatus, valves subdividing said pas sageway into separate compartments and means for delivering said material from the last of said compartments by gas pressure.

'21. An apparatus of the class described including a rotatably mounted body portion having a passageway along which matefial may be moved upon the rotation of said he .y portion, valves subdividing said passageway into separate compartments, means for roamtaining one of said compartments at a. pres sure above that of the atmosphere and a disposed passe gew ay,

valves subdipassageway,

use, its

valve controlled by'pass around the valve leading to said compartments.

22. An apparatus of the class described including a rotatable body portion having a passageway along which material may advance during the rotation of said body portion, gravity operated valves subdividing said passageway into a plurality of separate compartments, and means for maintaining one of said compartments at a pressure materially above that of the atmosphere.

An apparatus of the class described including a rotatable body portion having a passageway along which material may advance during the rotation of said body portion, gravity operated valves subdividing said passageway into a plurality of separate compartments, means for maintaining one of said compartments at a pressure materially above that of the atmosphere, and a conduit leading from said compartment and through which gas and said material may be continuously delivered during said rotation.

24:. An apparatus of the class'described including a rotatable body portion having a passageway along which material may ad- Vance during the rotation of said body portion means for subdividing said passageway into a plurality of separate compartments, means for maintaining one of said compartments at a pressure materially above that of the atmosphere, and a conduit leading from said compartment and through which gas and said material may be continuously de- '.-verecl during said rotation.

An apparatus of the class described, including a. drum having partitions therein forming a passageway along which material may advance upon the rotat on of said drum, movable means subdividing said pamageway into separate chambers or compartments and operating intermittently to permit the passage of material and a conduit leading from the terminal compartment of said passageand from which material may be delivered.

26. An apparatus of the class described including a drum having partitions therein forming a passageway along which material may advance upon the rotation of said drum,

. movable means subdividing said passageway into separate chambers or compartments and operating intermittently to permit the passage of material and a conduit leading from the terminal compartment of said passageway and from which material may be delivered by gas pressure.

27. An apparatus of the class described including a drum having a transverse partition adjacent to one end thereof, partitions subdividing the space between said partition and the adjacent drum head into a spiral flanges adjacent the periphery of said drum and upon the opposite side of said first mentioned partition for advancing material lengthwise {of said drum to the beginning of said spiral passageway and a conduit concentric with said drum and from which material may be delivered from the innermost portion of said spiral passageway. a

28. An apparatus of the class described including a drum having a transverse partition adjacent to one end thereof, partitions subdividing the spacebetween said partition and the adjacent drum head into a spiral passageway, flanges adjacent the periphery of said drum and forming a helical passage way for advancing material lengthwise of said drum to the beginning of said spiral passageway, a conduit concentric with said drum and from which material may be delivered from the innermost portion of said spiral passageway, and a screen preventing the admission of coarse material to said heli cal passageway.

29. An apparatus of the character described having a passageway along which material may advance upon the rotation of said apparatus, a gravity operated valve subdividing said passageway into separate compartments, a bypass connecting said compartments and a gravity operated valve controlling said by-pass.

30. An apparatus of the character described having a passageway along which material mayadyance upon the rotation of said apparatus la grav1ty operated valve subdividing said passageway into separate compartments, a'- by-pass connecting said compartments, and a gravity operated valve controlling said by-pass, said second mentioned valve being arranged to open prior to the opening of the" first mentioned valve during said rotation. 1

31. An apparatusbf the character described having a passageway along which material may advance upon the rotation of said apparatus, a gravity operated valve subdividing said passageway into separate compartments, a by-pass connecting said compartments, a gravity operated valve controlling said by-puss, and means for maintaining one oi said compartments at a pressure above that of the atmosphere, said second mentioned valve being arranged to open and permit the passage of gas to the opposite side of the first mentioned valve prior to the opening of the iatter.

32. An apparatus of the class described including a rotatable 'body having a plurality of separate compartments arranged in series and through which material may pass in succession, a prime mover connected to said body' portion for advancing said material and means for delivering material from said drum by the exhaust gas from said prime mover.

33. In combination, a movable body portion having a passageway along which material may advance, valves subdividing the said passageway into separate compartments, a prime mover connected to said body portion for advancing material along said passageway, and means for delivering the exhaust gas from said prime mover to one of said compartments to maintain the latter under a gas pressure above that of the atmosphere.

Signed at of New York and State of New York, this 9th day of December A. D. 1912.

GILBERT H. GILBERT.

Witnesses:

' C. WV. FAIRBANK, FLORENCE Lawns.

New York city, in the county 

